Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F293/00—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
  • C08F293/005—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation

Definitions

• the present invention relates to a new radical polymerization process giving access to block polymers, as well as the block polymers thus obtained.
• Block polymers are usually prepared by ionic polymerization. This type of polymerization has the disadvantage of only allowing the polymerization of certain types of apolar monomers, in particular styrene and butadiene, and of requiring a particularly pure reaction medium and temperatures often below ambient so as to minimize the parasitic reactions, hence severe implementation constraints.
• Radical polymerization has the advantage of being easily carried out without excessive purity conditions being met and at temperatures equal to or above ambient. However, until recently there was no radical polymerization process allowing block polymers to be obtained.
• Controlled radical polymerization has an advantage over conventional radical polymerization when it comes to preparing low molecular weight and functionalized chains (reactive telomeres). Such polymers are sought after for specific applications such as, for example, coatings and adhesives.
• the fraction of chains with at most one functional site becomes significant when the average degree of polymerization is less than a threshold value (e.g. 20 or 30).
• a threshold value e.g. 20 or 30.
• Controlled radical polymerization makes it possible to reduce, or even inhibit, the formation of these oligomers to zero or a functional site which degrades the performance in application.
• polymer is used to describe homopolymers or copolymers unless otherwise indicated.
• block polymer is understood to mean a copolymer comprising at least two successive sequences of blocks of monomer units of different chemical constitutions.
• the blocks can consist of a homopolymer or a polymer obtained from a mixture of ethylenically unsaturated monomers.
• the block can be a random copolymer.
• the block copolymer can comprise two blocks each made up of random copolymers.
• the ethylenically unsaturated monomers are such that the blocks obtained are of different natures.
• different natures is meant blocks made up of monomers of types different, but also blocks made up of monomers of the same type but in different quantities.
• An object of the present invention is to provide a new radical polymerization process using a new control agent.
• a second object of the invention is to propose a polymerization process during which the number-average molar masses M n of the polymers obtained are well controlled.
• Another aim is to propose a controlled radical polymerization process for the synthesis of functionalized polymers at the end of the chain.
• Another object is to provide polymers with a low polydispersity index (M / M n ), that is to say close to 1, Mw being the molecular weight by weight.
• R 2 , R 3 and R ' 2 identical or different, represent:. a hydrogen atom,
• a carbon ring or a heterocycle saturated or not, aromatic, optionally substituted
• R 2 and R 3 , or R 2 'and R 3 together, represent the atoms necessary to form a carbon ring or a heterocycle, saturated or not, aromatic, optionally substituted, and - p is between 2 and 10.
• the compound (III) useful in the process of the invention comprises a dithiophosphoroester function. Phosphorus due to its pentavalence increases the number and therefore the nature of the substituents.
• radicals R 2 and / or R 3 are -SR. , one, two or three active sites are then present in the compound (III).
• R 1 and R are a polymer chain, this polymer chain can come from a radical or ionic polymerization or from a polycondensation.
• the groups R 1f R /, R 2 and R 2 ′ and R 3 when they are substituted, can be substituted by substituted phenyl groups, substituted aromatic groups, saturated or unsaturated carbon rings, saturated or unsaturated heterocycles, or groups: aikoxycarbonyl or aryloxycarbonyl (-COOR), carboxy (-COOH), acyloxy (-O2CR), carbamoyl (-CONR2), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, maleidoido amidino, guanidimo, hydroxy (- OH), amino (-NR2), halogen, perfluoroalkyl C n F 2n + 1 , allyl, epoxy, alkoxy (-OR), S- alkyl, S-aryl, groups having a hydrophilic character or ionic such as the alkal
• R. and R / are substituted or unsubstituted alkyl groups, preferably substituted.
• the compounds (III) useful in the present invention are, for example, compounds III in which R or R / is chosen from:
• the compounds of formulas (IIIA), (IIIB) and (1110) are easily accessible. They can in particular be obtained by reaction between P 4 S 10 , K 2 CO 3 and a halogen derivative (Nizamov et al. Phosphorous Suif ur and Silicon, vol. 132, 85-100 (1998).
• Another access route consists reacting an alkali metal salt of a dithiophosphonic acid with a halogen derivative (Mastryukova et al, Bull. Acad. Soi. USSR. Div. Chem. Sci (Engl Transi), Vol. 27, 1917 (1978)).
• the process of the invention is in all cases implemented in the presence of a source of free radicals, however, for certain monomers, such as styrene, the free radicals making it possible to initiate the polymerization can be generated by the monomer ethylenically unsaturated, itself at sufficiently high temperatures generally above 100 ° C. It is not, in this case, necessary to add an additional source of free radicals.
• the source of free radicals useful in the process of the present invention is generally a radical polymerization initiator.
• the radical polymerization initiator can be chosen from the initiators conventionally used in radical polymerization. It can for example be one of the following initiators: - hydrogen peroxides such as: tertiary butyl hydroperoxide, cumene hydroperoxide, t-butyl-peroxyacetate, t-butylperoxybenzoate, t-butylperoxyoctoate, t-butylperoxyneodecanoate, t-butylperoxyisobutarate, lauroyl peroxide, t-amylperoxypivalte, t-butylperoxypivalate, dicumyl peroxide, benzoyl peroxide, potassium persulfate, ammonium persulfate,
• - azo compounds such as: 2-2'-azobis (isobutyronitrile), 2,2'-azobis (2-butanenitrile), 4,4'-azobis (4-pentanoic acid), 1,1 ' -azobis (cyclohexane-carbonitrile), 2- (t-butylazo) -2-cyanopropane, 2,2'-azobis [2-methyl-N- (1, 1) - bis (hydroxymethyl) -2-hydroxyethyl] propionamide, 2,2'-azobis (2-methyl-N-hydroxyethylj-propionamide, 2,2'-azobis dichloride (N, N'-dimethyleneisobutyramidine), 2,2'-azobis dichloride (2- amidinopropane), 2,2'-azobis (N, N'-dimethyleneisobutyramide), 2,2'-azobis (2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide), 2,2'-azobis (2
• the quantity of initiator to be used is determined so that the quantity of radicals generated is at most 50 mol% relative to the quantity of compound (III), preferably at least plus 20% by mole.
• the ethylenically unsaturated monomers useful in the process of the present invention are all the monomers which polymerize in the presence of compound (III), to give active polymer chains.
• ethylenically unsaturated monomers are for example
• - ethylenic unsaturated mono- and dicarboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and the mono-alkyl esters of dicarboxylic acids of the type mentioned with the alkanols preferably having 1 to 4 carbon atoms and their N-substituted derivatives,
• amides of unsaturated carboxylic acids such as acrylamide, methacrylamide, N-methylolacrylamide or methacrylamide, N-alkylacrylamides.
• ethylenic monomers comprising a sulfonic acid group and its alkali or ammonium salts, for example vinylsulfonic acid, vinylbenzene sulfonic acid, alpha-acrylamido methylpropane-sulfonic acid, 2-sulfoethylene-methacrylate,
• - amides of vinylamine in particular vinylformamide or vinylacetamide, - unsaturated ethylenic monomers comprising a secondary, tertiary or quaternary amino group, or a heterocyclic group containing nitrogen such as for example vinylpyridines, vinylimidazole, ( aminoalkyl meth) acrylates and aminoalkyl (meth) acrylamides such as dimethylaminoethyl acrylate or -methacrylate, ditertiobutylaminoethyl acrylate or -methacrylate, dimethylamino methyl acrylamide or - methacrylamide, or zwitterionic monomers such as for example l ' sulfopropyl (dimethyl) aminopropyl acrylate,
• - dienes for example butadiene, chloroprene,
• (meth) acrylic esters we mean the esters of acrylic acid and methacrylic acid with alcohols C ⁇ ⁇ C-
• Vinyl nitriles more particularly include those having 3 to 12 carbon atoms, such as in particular acrylonitrile and methacrylonitrile.
• the amides of vinylamine for example vinylformamide or vinylacetamide, are preferably used as ethylenically unsaturated monomers. Then, the polymer obtained is hydrolyzed at acidic or basic pH.
• vinyl esters of carboxylic acid such as for example vinyl acetate, are preferably used as ethylenically unsaturated monomers. Then, the polymer obtained is hydrolyzed at acidic or basic pH.
• the ethylenically unsaturated monomers can be used alone or in mixtures.
• R 2 and R 3 identical or different, represent:
• R 2 and R 3 together, represent the atoms necessary to form a carbon ring or a heterocycle, saturated or not, aromatic, optionally substituted, n is greater than or equal to 1, preferably greater than 6, - V, V, identical or different, represent: H, an alkyl group or a halogen,
• R 4 represents H, a halogen or a group R 4) OR 4 , O 2 COR 4 , NHCOH, OH, NH 2 , NHR 4 , N (R 4 ) 2 , (R ⁇ N + O " , NHCOR 4 , CO 2 H, C ⁇ 2R, CN, CONH2, CONHR 4 or CON (R 4 ) 2, in which R 4 is chosen from alkyl, aryl, aralkyl, alkaryl, alkene or organosilyl groups, optionally perfluorinated and optionally substituted with one or more carboxyl, epoxy, hydroxyl, alkoxy, amino, halogen or sulfonic groups, and
• - b is 0 or 1.
• the polymerization can be carried out in bulk, in solution; as an emulsion, dispersion or suspension. Preferably, it is used in solution or in emulsion.
• the method is implemented semi-continuously.
• the temperature can vary between room temperature and 150 ° C depending on the nature of the monomers used.
• the instantaneous polymer content relative to the instantaneous amount of monomer and polymer is between 50 and 99
• % by weight preferably between 75 and 99%, even more preferably between 90 and 99%. This content is maintained, in known manner, by controlling the temperature, the rate of addition of the reagents and optionally the polymerization initiator.
• the method is implemented in the absence of UV source, by thermal ignition.
• the process of the invention can be carried out using a mixture of ethylenically unsaturated monomers.
• a statistical first generation polymer is obtained.
• monomers of particular natures for example hydrophilic monomers and hydrophobic monomers and the amount of each of these monomers in the block, a block having particular properties is obtained. This procedure is particularly advantageous when the polymer of first generation thus obtained is an intermediate in the preparation of a block copolymer.
• the present invention also relates to a process for the preparation of a Nth generation block copolymer, by radical polymerization, N being greater than or equal to 2, which comprises:
• a second generation block copolymer can be obtained by a process which comprises the radical polymerization of a composition comprising:
• At least one ethylenically unsaturated monomer a source of free radicals
• the first generation polymer obtained by radical polymerization of the composition containing the compound (III) and of ethylenically unsaturated monomer, the block thus obtained being of a different nature from the polymer of first generation.
• a first generation polymer is synthesized from a composition comprising one or more ethylenically unsaturated monomers, from a source of free radicals and from a compound of formula
• step (1) the first generation polymer obtained in step (1) is used to prepare a diblock copolymer (second generation) by bringing this polymer into contact first generation with one or more ethylenically unsaturated monomers and a source of free radicals, the block obtained in step (2) being of a different nature from the first generation polymer of step (1).
• This step (2) can be repeated with new monomers and the diblock copolymers obtained to synthesize a new block and obtain a triblock copolymer.
• the polymerization step can thus be repeated as many times as necessary from a block copolymer to obtain a copolymer with an additional block.
• the process of the invention thus makes it possible to obtain a diblock copolymer of general formula (I):
• composition comprising:
• R. represent:
• R 2 and R 3 identical or different, represent:. a hydrogen atom
• a carbon ring or a heterocycle saturated or not, aromatic, optionally substituted
• R 2 and R 3 together, represent the atoms necessary to form a carbon ring or a heterocycle, saturated or not, aromatic, optionally substituted,
• - V, V, W and W identical or different, represent: H, an alkyl group or a halogen, - X, X ', Y and Y', identical or different, represent H, a halogen or a group R 4 , OR 4 , O 2 COR 4 , NHCOH, OH, NH 2 , NHR 4 , N (R 4 ) 2 , (R 4 ) 2N + O-, NHCOR 4 , CO 2 H, C ⁇ 2R 4 , GN, CONH2, CONHR 4 or CON (R 4 ) 2, in which R 4 is chosen from alkyl, aryl, aralkyl, alkaryl groups , alkene or organosilyl, optionally perfluorinated and optionally substituted by one or more carboxyl, epoxy, hydroxyl, alkoxy, amino, halogen or sulfonic groups, and
• the ethylenically unsaturated monomers which are useful are those described above.
• the above process is described from a polymer (II) obtained from a compound of formula (IIIA) however this teaching is directly applicable to the polymers obtained from compounds (IIIB) and (HIC).
• the compounds of formula (IIIA) when R 2 and / or R 3 represent -SR ⁇ (IIIB) and (HIC) are particularly advantageous because they make it possible to grow a polymer chain on at least two active sites. With this type of compound, it is possible to save on polymerization stages in order to obtain a copolymer with n blocks.
• p is 2 in formula (IIIB) or (NIC)
• the first block is obtained by polymerization of a monomer M1 in the presence of the compound of formula (IIIB) or (MIC). This first block can then grow at each of its ends by polymerization of a second monomer M2.
• a triblock copolymer is obtained, this triblock copolymer can itself grow at each of its ends by polymerization of a third monomer M3.
• a "pentabloc" copolymer is obtained in only three stages. If p is greater than 2, the process makes it possible to obtain homopolymers or block copolymers whose structure is "multi-arm” or star. According to this process for the preparation of block polymers, when it is desired to obtain polymers with homogeneous blocks and not with a composition gradient, and if all the successive polymerizations are carried out in the same reactor, it is essential that all the monomers used during of a step have been consumed before the polymerization of the next step begins, therefore before the new monomers are introduced.
• the polymerization step is carried out with a composition containing a mixture of ethylenically unsaturated monomers.
• the present invention also relates to the first generation polymers and the block polymers which can be obtained according to any one of the methods of the invention.
• These polymers have a low polydispersity index and a controlled molecular weight.
• the polydispersity index is at most 2, preferably at most 1.5.
• the block polymers comprise at least two polymer blocks chosen from the following associations:
• One of the blocks can also consist of a random copolymer obtained from a mixture of ethylenically unsaturated monomers.
• the reactive ends of the block polymer can be cleaved to form a polymer whose ends are thiols or hydrogen atoms.
• These modifications can be implemented by reduction and / or hydrolysis.
• the polymerization reactions are carried out in Schlenk type equipment.
• the mixture contained in the reactor is connected to a vacuum ramp, immersed in liquid nitrogen, then three freeze-vacuum-return cycles at room temperature in order to degas the mixture.
• the reactor is then left under static vacuum at the appropriate temperature.
• Kinetic monitoring is carried out by taking samples of the reaction medium over time, under a stream of nitrogen. After each sampling, a new degassing operation is carried out as described above.
• the conversion of the monomer is determined by gravimetry after evaporation of the residual monomer under vacuum.
• the (co) polymers are analyzed by steric exclusion chromatography (SEC) using THF as elution solvent; the molar masses are expressed in polystyrene equivalents (g. mol "1 ).
• SEC steric exclusion chromatography
• Example 2.1 homopolystyrene obtained from compound (III A1)
• Example 2.2 POLY block copolymer (STYRENE-b-METHYL ACRYLATE) from a homostyrene
• a solution is prepared from:
• AIBN azobis-isobutyronitrile

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• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Graft Or Block Polymers (AREA)

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• 2000
  • 2000-07-28 FR FR0009952A patent/FR2812293B1/fr not_active Expired - Fee Related
• 2001
  • 2001-07-20 WO PCT/FR2001/002374 patent/WO2002010223A2/fr not_active Ceased
  • 2001-07-20 AU AU2001279882A patent/AU2001279882A1/en not_active Abandoned
  • 2001-07-20 EP EP01958146A patent/EP1309629B1/de not_active Expired - Lifetime
  • 2001-07-20 US US10/343,045 patent/US7247688B2/en not_active Expired - Fee Related
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